Welcome to the AC Tropical Fish aquarium forum. Our aquarium forum is the place to discuss any aquarium related issue in a friendly environment. Our aquarium forum welcomes aquarists of all levels from beginners to experts. Please ask a question in the how to section of our forum or read the FAQ section if you have any questions. register to and become a part of our friendly aquarium forum community today.

PH drop & testing KH & GH

0

While my tank was cycling (fish in) I noticed my ph would drop so I tested my tap waters KH & GH and if memory serves I had a reading of 53.7 ppm GH/KH so I began adding crushed coral to my canister filter (about 1 cup) and my ph held between 7.2 - 7.6 (ph out of the tap is 7.6). So between adding the crushed coral and doing daily 50% water changes my ph stayed stable.

Now that my tank has cycled I started testing my water and doing water changes only on a weekly basis and my ph is again showing issues of instability. During the day it tests at about 7.23 but has dropped all the way to 6.62 by the morning then it starts to climb again. Adding fresh crushed coral to the filter and adding an additional cup of it (hanging in a media bag in the tank) hasn't really helped the problem. I've also done 3 days of 50% + water changes and that hasn't made much of a difference either. Water parameters are 0 ammonia / 0 nitrites / 0 nitrates (usually 5-10 but have just done 3 days of pwc's).

I tested the tap water again this evening - PH 7.6 out of the tap and the KH/GH were as follows: KH = 3 drops to turn water yellow (light yellow not dark). GH = 6 drops to turn water green (light green not dark).
What exactly is my ppm GH/KH?

Even more confusing is my 10 gallon QT tank PH has tested 7.6 for three days. No live plants in there or driftwood though, I do have 5 live plants and a 10" x 2" piece of driftwood in the tank with the ph issues.

It sounds to me like dissolved CO2 is building up during the night, making the PH drop. You can add an airstone at night to help drive off the excess gasses.

Liters to Gallons conversion calculator
"Keeping fish for any period of time doesn't make you experienced if you're doing it wrong. What does, is acknowledging those mistakes and learning from them." ~Aeonflame
"your argument is invalid." ~Mommy1

When I go fishing I just throw sharp rocks in the water and wait for the dead fish to float to the top... KingfisherEverything happens for a reason. Sometimes that reason is you are stupid and make bad decisions. I think my fish is adjusting well to the four gallon, He's laying on his side attempting to go to sleep on the bottom of the gravel.
Imitation is the sincerest form of flattery. Dear naps, sorry I hated you so much when I was a child... Love me

What is the GH and KH in the tank? It is normal for pH to fluctuate in nature, sometimes well over a point, I think stable GH and KH are more important, but I know others will come along and disagree.
[url